Ok so we got that out the way so now what about the speculations of what happens when you are sent back.

You are reborn again obviously so you start from a child. But would you retain your memories, appearance, or soul level?

Aizen is gangsta for making everyone wear white.

Tousen: "So what are we going to wear anyway? how do we tell each other apart from the shinigami?"
Aizen: "I GOT IT....lets wear exactly what they wear...but make it WHITE!"
Ichimaru: "OH SH*T, now THATS gangsta!"
Tousen: "....even I wouldn't say that..."
Aizen: "Loosen up Tousen...check this out...lets show him Gin!"

If souls die, i think its safe to assume that in the bleach universe, they just cease to exist. Saying that there is a hell and heaven ON TOP soul society and the hollow place is just too much for me, lol

Ok so we got that out the way so now what about the speculations of what happens when you are sent back.

You are reborn again obviously so you start from a child. But would you retain your memories, appearance, or soul level?

I don't think you'd retain your memories, appearance (to an extent), or soul level. You'd still have the same potential you had in this life and likely a very similar personality, you (the core person) would still be there.

'tis true. Hueco Mundo is not hell, hell is worse. And if there is a hell, Aizen may have been speaking literally when he mentioned God in his one speech. (The one where he was saying how he would be the master of everyone and surpass God himself.)

from all the info they gave in bleach, this is how i think the bleach life (and afterlife) system works

hueco mundo <--> earth <--> soul society
|
|
V
hell

there should be a double arrow from soul society and hueco mundo too. kinda like a triangle.

people die on earth and become spirits. spirits are either sent to SS (soul burial) or turn into hollows (who can then go to hueco mundo).

if a hollow is cut with a zanpakutou, it either goes to soul society, or goes to hell, depending on the sins during the life.

if a hollow is merely destroyed, they just disappear.

since spirits seem to age, they most likely also die of aging. when they die (aging or otherwise), they get reborn on earth. i don't think there's any special ritual for that. it's like they're waiting in line, and whenever a baby is born, they get put into the baby.